This retrospective study on 85 adult obstructive sleep apnoea (OSA) patients provides further interesting information for sleep surgeons. These patients were all investigated with polysomnography (PSG) and drug induced sleep endoscopy (DISE). They all then underwent a simple uvulopalatoplasty with or without tonsillectomy, and had their PSG repeated to assess the impact of the intervention. Contemporary sleep surgeons would act upon the DISE findings and individualise the surgery to include as a minimum tongue base reduction and expansion pharyngoplasty. This study shows the impact of not individualising surgery based on DISE findings. The obvious excellent results of tonsillectomy in patients with grade III and IV sized tonsils was seen, but these figures have been established by Friedman et al with his staging system for surgery for OSA patients.
The results also show that patients who were identified as having tongue base collapse and patients with circumferential collapse at the velum on DISE had poor surgical outcomes. Although these findings are not overly new, this study represents a form of validation for DISE.
The ability of DISE to prognosticate success rates implies a measure of legitimacy in the investigation. In UK centres where expansion pharyngoplasty and/or tongue base reduction techniques are not funded, DISE therefore represents a low morbidity method of categorising patients for OSA surgery. Evidence of these characteristic obstructive levels could be used as exclusion criteria for surgery on the NHS. In Friedman stage 1 patients however, surgery represents an 80% chance of cure which patients can consider as a viable alternative to lifelong CPAP.
